Michael addition of ortho-lithiated aryloxiranes to α,β- unsaturated malonates: Synthesis of tetrahydroindenofuranones

Organic Letters

Volumn 10, Issue 10, 2008, Pages 1947-1950

  Salomone, Antonio ^a   Capriati, Vito ^a   Florio, Saverio ^a   Luisi, Renzo ^a  

^a UNIVERSITY OF BARI   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

EPOXIDE; FURAN DERIVATIVE; INDENE DERIVATIVE; LITHIUM; MALONIC ACID DERIVATIVE; ORGANOMETALLIC COMPOUND;

ARTICLE; CHEMICAL STRUCTURE; CHEMISTRY; CYCLIZATION; STEREOISOMERISM; SYNTHESIS;

CYCLIZATION; EPOXY COMPOUNDS; FURANS; INDENES; LITHIUM; MALONATES; MOLECULAR STRUCTURE; ORGANOMETALLIC COMPOUNDS; STEREOISOMERISM;

EID: 47049095653     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol800437s     Document Type: Article

References (18)

1. For selected reviews on functionalized organolithium compounds, see:
2. (a) Wu, G.; Huang, M. Chem. Rev. 2006, 106, 2596-2616.
3. (b) Najera. C.; Yus. M. Curr. Org. Chem. 2003, 7, 867-926.
4. Capriati. V.; Florio, S.; Luisi, R.; Musio, B. Org. Lett. 2005, 7, 3749-3752.
5. Capriati, V.; Florio, S.; Luisi, R.; Perna, F. M.; Salomone, A. J. Ore. Chem. 2006, 71, 3984-3987.
6. Capriati, V.; Florio, S.; Luisi, R.; Perna, F. M.; Salomone, A.; Gasparrini, F. Org. Lett. 2005, 7, 4895-4898.
7. Preliminary experiments were conducted using methylcinnamate, chalcone, and trans-cinnamaldehyde: there was no reaction when ortholithiated trans-tilbene oxide was treated with methylcinnamate, and only 1,2-addition products were obtained in the case of chalcone and trans-cinnamaldehyde (see ref 3). For examples of Michael additions promoted by organolithium compounds, see: Curtis, M. D.; Beak, P. J. Org. Chem. 1999, 64, 2996-2997, and refs cited therein.
8. The Michael addition of aryllithiums to α,β-unsaturated malonates was reported by Kende and coworkers, as a key step in the racemic synthesis of an epipodophyllotoxin derivative. Such a methodology was employed in the construction of the tetrahydronaphthalene core starting from an orthobromobenzylether: Kende, A. S.; King, M. L.; Curran, D. P. J. Org. Chem. 1981, 46, 2826-2828.
9. 4(cat) in order to obtain exclusively the desired indenofuranones 4e-g (for details, see Supporting Information).
10. The one-pot procedure was also employed for the synthesis of 4g obtained in 50% yield (dr 80/20) after stirring the reaction mixture for one day.
11. Starting from cis-1d, we thought that it would be possible to make epimeric tetrahydroindenofuranone diast-4f with the stereogenic center C3 "R"-instead of "S"- configured, as previously synthesized starting from trans-1d. All the attempts carried out by using ortho-lithiated civ-1d resulted in a very complex mixture of products containing only traces of a 60/40 diastereomeric mixture of diast-4f. After column cromatography, it was possible to isolate and characterize only the major diastereoisomer (for details, see Supporting Information).
12. Muraoka. O.; Tanabe, G.; Kyohko. S.; Minematsu, T.; Momose, T. J. Chem. Soc., Perkin Trans. 1 1994, 1833-1845.
13. For all tetrahydroindenofuranones 4a-g and 6a-c, it is reasonable to assume that, for thermodynamic reasons, the γ-lactone ring may be fused to the indane system only in a cis fashion.
14. Semiempirical calculations on the substituted indenofuranone systems confirm such values of dihedral angles.
15. Neuhaus, D.; Williamson, M. The Nuclear Overhauser Effect in Structural and Conformational Analysis; VCH: New York, 1989; p 264.
16. To the best of our knowledge, the sole methodology described in the literature, concerning the construction of the tetrahydroindeno[l,2-c]furan-l- one skeleton, was based on the photochemical rearrangement of benzylfuranones, see: Muraoka, O.; Tanabe, G.; Sano, K.; Momose, T. Heterocycles 1992, 34, 1093-1096.
17. For the synthesis and biological evaluation of structural analogues of epipodophyllotoxins, see: Klein, L. L.: Yeung. C. M.: Chu, D. T.; McDonald, E. J.; Clement, J. J.; Plattner, J. J. J. Med. Chem. 1991, 34, 984992.
18. For a recent strategy about the synthesis of Podophyllotoxin and its analogues, see: Wu, Y.; Zhang, H.; Zhao. Y.; Zhao, J.; Chen, J.; Li, L. Org. Lett. 2007, 9, 1199-1202.